1. Field
One or more embodiments relate to a light scanning unit and an image forming apparatus employing the same, and more particularly, to a light scanning unit for reflecting and deflecting luminous flux output from a light source toward a light deflector to form an image on a surface to be scanned, and an image forming apparatus employing the same and performing an electrophotographic process.
2. Description of the Related Art
Electrophotographic image forming apparatuses such as laser printers, digital copiers, multifunction printers (MFPs), etc. have a structure in which light is scanned onto a photosensitive body by using a light scanning unit to form an electrostatic latent image, a formed electrostatic latent image is developed into a developed image by using a developer such as toner, and the developed image is transferred onto a printing medium.
The light scanning unit generally uses plastic resin as a material for a housing for mounting optical parts such as a light source or a light deflector. However, the housing formed of a plastic resin material has a problem in that parts of the housing may be thermally deformed according to a change in peripheral and internal temperatures and a position of the photosensitive body where an image is formed by a light beam may be deviated.
The tendency for a change in the image forming position on the photosensitive body due to the thermal deformation may be stronger in the light scanning unit for scanning a plurality of light beams such as a color image forming apparatus. In a color image forming apparatus of the related art in which a plurality of luminous fluxes are scanned by using one light deflector, in order to guide the luminous flux after scanning to each photosensitive body corresponding to a different color, the luminous fluxes are obliquely incident with respect to a plane that is perpendicular to a rotational shaft of a deflection unit and then the luminous fluxes are split. An oblique incident type light scanning unit is a structure of reducing material costs by making a compact optical path layout and reducing the number of parts. In the color image forming apparatus of the related art, to address the thermal deformation problem, changing tendencies of the image forming positions on the photosensitive body, which occurs due to heating of light sources and a change in the peripheral temperature, may be congruent to each other by fixing flanges in which light sources are assembled on the housing by using elastic members and varying pressing-directions of the elastic members in which the elastic members are assembled according to the flanges.
However, for a light scanning unit in which a distance between a plurality of light sources is narrow, for example, less than or equal to 12 mm, it is difficult to separately accommodate a holder (flange) for each light source and to make a space for assembling the elastic members on the holder (flange). Also, as the elastic members are assembled for each light source, the number of parts and the number of steps are increased so that the material costs are increased and a process is complicated.